extremely faint millimeter sources identified by multi-field deep...

Extremely Faint Millimeter Sources Identified by Multi-Field Deep ALMA Survey and Subaru Follow-up Spectroscopy

Fujimoto et al. 2016 (ApJS, 222, 1) Fujimoto et al. in prep.

Seiji Fujimoto 11/28-12/2/2016 “Panoramas of the Evolving Cosmos” @ Hiroshima

Seiji Fujimoto (U. Tokyo) Masami Ouchi (U. Tokyo, IPMU) Yoshiaki Ono (U. Tokyo) Takatoshi Shibuya (U. Tokyo) Masafumi Ishigaki (U. Tokyo) Hiroshi Nagai (NAOJ) Rieko Momose (NAOJ)

OUTLINE

- Resolve the Cosmic Infrared Backgournd light (CIB)

- Origin of the Faint mm Source


This work: Largest dataset of multi-field deep ALMA -> Resolve CIB / Physical origins

Cosmic Infrared Background-light (CIB)Dole+2006 Before ALMA

Submm galaxies (SMGs) ~1.0 − 10mJy ~10% (e.g., Scott+12)

ALMA Sources ~0.1 − 1.0 mJy ~60% (Hatsukade+13, Ono+14, Carniani+15)

Intro Data/Analysis Galaxy Bias Counterpart

CIB has not been fully resolved…

Number Counts Resolving CIB Subaru

CIB~1mm (COBE)

Hughes+98

ALMA (Carniani+15)


Sample Selection

Criteria: • Noise level < 0.1 mJy • No too Bright/Extended Sources

DATA: ALMA Band 6 & 7 (~submm/mm) • Our quite deep 4 ALMA data(Ouchi+13, etc) • ALL ALMA data so far archived (2012/12-2015/7)

Total: 67 deep maps Obs. hrs ~100 hrs (cf. typical obs. hrs ~4 hrs)

Intro

Himiko

z=7.3 LAE

z=6.5 LAE

z=5.7 LAE

Our Deep ALMA Maps

Data/Analysis Galaxy Bias CounterpartNumber Counts Resolving CIB Subaru


Cluster Data (1 map)• Multiple image: Diego+14 • Optical Catalog: Diego+14, Coe+10 • Software: GLAFIC (Oguri 10)

A1689

(e.g., Ishigaki+15)

A1689Critical Line

Intro Galaxy Bias CounterpartNumber Counts Resolving CIB SubaruData/Analysis



Field Data (66 maps)

Total Sources : 133

Detection Example

~5σ

0.6 × 0.8 “

←FWHM of PB

~6σ・・・・・・

Examples

* Original Target Sources Removed


Rs (S/N): Spurious Source Rate C (S/N): Completeness

Data Analysis

1 - RS(S/N)Neff = C(S/N)Completeness Survey AreaPositive & Negative Peaks

Resolve CIB -> Derive Number Counts

(e.g., Hatsukade+13, Ono+14, Carniani+15)


Neff: Effective Number


Fujimoto et al. 2016

Recent ALMA

This work

We successfully derive number counts in the range of 0.018 - 1.2 mJy.

Number Counts at 1.2 mmIntro Data/Analysis Galaxy Bias CounterpartNumber Counts Resolving CIB Subaru


This work

Recent ALMA~60%40%

SMGs 1) Flattening 2) Truncation below 0.02 mJy Limiting Flux [mJy]~0.02mJy

α = −2.1−1.0• < 0.02 mJy

sources would be negligible

Intro Data/Analysis Galaxy Bias CounterpartNumber Counts Resolving CIB Subaru


Field-to-Field Scatter = Galaxy Bias + Poisson error

・・・

0

0 0

0

0

1 1

1

1 1 13

3 3 1

Field-to-Field Scatter - Poisson error = Galaxy Bias

Faint ALMA Sources bg < 3.5 (ΛCDM->) MDH < 5 × 1012 Msun　

2

2 1

1

1

0 1

0

3 0 12

1 4 0

0

0 0

0

0

1 1

1

1 1 13

3 3 1

2

2 1

1

1

0 1

0

3 0 12

1 4 0

bg: galaxy bias σV: matter variance σN: dispersion of source counts N: mean source counts

(e.g., Robertson+10)

Counts-in-Cells

Examples

1. Statistical Approach: Cluster AnalysisIntro Data/Analysis Galaxy Bias CounterpartNumber Counts Resolving CIB Subaru


• Faint ALMA Sources bg < 3.5　

Faint ALMA Sources ＝ sBzK, LBGs, LAEs?

• SMGs / DRGs / pBzK bg ~ 5 - 7　• sBzK / LBGs / LAEs bg ~ 2 - 3　

1. Statistical Approach: Cluster Analysis

b g

R e d s h i f t

sBzK LAE

Massive

low mass

H a l o M a s s



• Multi-wavelength data(X-ray, Optical, IR, radio)

• Opt.-NIR Counterparts -> ~60±20%

Faint ALMA Sources (red contour) w(/o) opt. counterparts (B,r,z)

２. Individual: Opt.-NIR Counterparts

60％

S1.2mm (mJy)

Coun

t. fr

actio

n

0.01 0.1 1.0

0.2

0.4

0.6

0.8

1.0

Source Flux vs Count. fraction

Lensed Field

?

40％



BzK Color Diagram BX/BM Color Diagram

z~3-5

z~2

z~2

z~3-5

pBzK

Photometric Properties ①

Majority of Faint ALMA Sources -> sBzK / LBG(BX/BM)

40%60%

Intro Data/Analysis Galaxy BiasNumber Counts Resolving CIB SubaruCounterpart

sBzK


Photometric Properties ②① Clustering

(Statistical) ② Opt. Counterparts (Individual)

Faint ALMA Sources (60%)

Optically Selected SFGs

←

AGN

Star burst

AGN diagram

Faint ALMA Sources -> x AGN

o Optically selected SFG

40%60%

Intro Data/Analysis Galaxy BiasNumber Counts Resolving CIB SubaruCounterpart


Subaru NIR Spectroscopy

• Five faint ALMA sources • To determine redshift, Z


40%60%

A3,A4A1,A2,A5

Date: 6/19-6/21/2016 Mode: MORICS/HK500


Other 3 faint ALMA sources … • No lines are detected


Subaru NIR Spectroscopy

Hα

Hα[OIII]

A5

A1

z=2.50 12+log(O/H) < 8.2

z=2.63 (Jullo+10) 12+log(O/H) < 8.2

A4

~

~

?

A0 ?

A2


SummaryLargest ALMA Dataset (133 down to 0.02 mJy) • Resolve the CIB ~100% • Statistical / Individual 　- galaxy bias: bg < 3.5 　- Opt.-NIR counterparts: (60%) Opt. SF galaxies z~2-3 　 (40%) unknown

40%60%unknow

Opt. NIR galaxy

?Faint ALMA


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